Role-playing games (or RPGs) originated in interactive literature and became popular in the form of tabletop role playing games. Such games have developed into computer games, many of which were originally single-player text-based games. Computer-based role playing games have developed over the years, adding graphics, multiplayer capabilities, and other features.
Computer role playing games are distinguished from other computer adventure games primarily by the player being allowed to create a character or a group of characters by choosing ability scores, equipment and other attributes, similar to a character generation process that takes place in traditional tabletop role playing games. Unlike tabletop role playing games, however, computer role playing games largely remain a single-player experience or have limited multiple player capabilities. Like other kinds of computer adventure games, success is achieved by finding a correct path through the pre-programmed obstacles and hazards. Several conventional computer role-playing games include, for example, role-playing games from Strategic Simulations, Inc. (SSI) based on the popular Advanced Dungeons & Dragons tabletop role-playing games available from TSR, Inc., Ultima Series role-playing games available from Origin Systems, and more recently the Diablo role-playing game available from Blizzard Entertainment.
Multi-user computer role playing games are known by a variety of acronyms, which normally indicate stylistic rather than technical differences. The majority of these games fall into two broad categories. Multi-User Dungeons (or MUDs) type games favor action and combat, with players fighting monsters and even other players in the effort to become more powerful. By contrast, games of a Multi-User Shared Hallucination (MUSH) or Multi-User Shared Environment (MUSE) type place more emphasis on nonviolent interaction between players. In these game types, some game sessions become intensely political as players plot and compete for influence, while others are closer to group storytelling than to a competitive game.
Apart from the shared characteristics of supporting multiple players over a network or the Internet, and allowing each player a single game persona or character, features of these types of games are various. For instance, some games are entirely human-moderated, and others are computer-moderated to varying degrees. Some are entirely text-based, and some use graphics and sound to varying degrees. A list of example MUDs and other similar games may be found in the USENET newsgroup rec.games.mud.misc.